Eggs are classified based upon the minimum weight per dozen thereof. Presently, the classification is made at three ounce increments, and there are 6 classes in the classification, starting from a "peewee" class of eggs which weigh between 15-17 ounces per dozen, a "small" class of eggs which weigh between 18-20 ounces per dozen, and so on, to a "jumbo" class of eggs which weigh between 30-32 ounces per dozen. However, the classification may be increased to include eggs which weigh between 33-35 ounces per dozen (which are sometimes called "large jumbo" class) and eggs which weigh over 36 ounces per dozen (which are sometimes called "super jumbo" class).
To store, ship and merchandize the larger classes of eggs, the size of egg cartons will have to be increased. However, when larger egg cartons are used to hold larger eggs, it is preferable that they can still be stacked and fit into existing egg carton containers (i.e., the egg baskets). This becomes a limitation to the design of larger egg cartons. For example, egg cartons generally have a plurality of cells each for holding an egg. When a larger egg is placed into a cell, the cell will have to expand. However, clearance allowable for such expansion will decrease when larger egg cartons must be placed into existing egg carton containers.
Moreover, as the size of the egg cartons increases, conventional egg carton structures are found to be unsatisfactory for several reasons. One of the problems, for example, is that conventional egg cartons, while strong enough to hold smaller eggs, will lack sufficient strength and resiliency to hold the larger eggs, which are heavier and usually more fragile.
The increase in size of egg cartons also manifests several other defects in conventional egg carton structures. For example, common thermoplastic polystyrene egg cartons generally have a locking flap, with one or more nubs, which is built to have a tendency to push itself outward so that, when closed, the nubs can engage corresponding holes in the cover. To close the carton, the flap must be pushed inward, usually at its center, so that the cover can cover the flap. However, as the egg cartons become longer and because of the resilient nature of the material, it will become more difficult to push the flap completely inside the cover by pushing the center.
A general object of the present invention is to provide egg carton improvements which can facilitate the storage, shipping and merchandizing of large size eggs and use of the egg carton by customers.
For example, one important object of the present invention is to provide an egg carton structure wherein expansion of a cell can be biased towards the interior of the egg carton, so that larger egg cartons can still fit in conventional egg carton containers, and the cells can still expand to accommodate large eggs.
According to one aspect, the present invention provides an egg carton which is integrally molded from a sheet of polystyrene material, and which has a cover and a tray. The tray is hingedly connected to the cover and has a plurality of cells. Each cell has a bottom, a top edge, at least one individual exterior wall and at least one individual interior sidewall. The exterior and interior sidewalls extend from the bottom to surround the cell, with the interior sidewall of adjacent cells interconnecting at an apex. The interior and exterior sidewalls of each cell are contoured such that expansion of the cell is biased toward the interior of the egg carton.
According to another aspect, the present invention provides an egg carton which is integrally molded from a sheet of polystyrene material, and which has a cover and a tray. The tray is hingedly connected to the cover and has a plurality of cells. Each cell has a bottom, and exterior and interior sidewalls which extend from the bottom to surround the bottom. The cover has a recess for storing printed material.
In still another aspect, the present invention provides an egg carton which is integrally molded from a sheet of polystyrene material, and which has a cover and a tray. The tray has a plurality of cells. Each cell has a bottom, and exterior and interior sidewalls which extend from the bottom to surround the cell. The egg carton also has a hinge interconnecting a first wall of the tray and a first wall of the cover. The egg carton also has a locking flap extending from a second wall of the tray, and which has one or more nubs for engaging corresponding one or more holes in the second wall of the cover. The flap has a bottom edge connecting to the second wall, a top edge opposite the bottom edge and two side edges. The top edge of the flap is shorter than the bottom edge of the flap by a length which is a function of the resiliency and length of the flap.
In still another aspect, the present invention provides an egg carton which is integrally molded from a sheet of polystyrene material. The egg carton has a cover and a tray hingedly connected to the cover. The tray has a plurality of cells arranged in a matrix, with at least two parallel rows of cells and at least four cells in each row, each cell having a bottom, and exterior and interior sidewalls extending from the bottom to surround the cell. The egg tray has a plurality of intersections formed by sidewalls of groups of four adjacent cells. The intersections include a first intersection located at substantially the center of the tray, and at least two second intersections one on each side of the first intersections removed from the center, and where each of the second intersections is lower than the first intersection.